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' H. R. STAFFORD.

STEAM ENGINE VALVE CHEST.

APPLICATION F| LED MAR. 29. i916.

2 SHEETS-SHEET l.

Patented. Aug. 8, 1916.

L JLL H. R. STAFFORD.

V STEAM ENGINE VALVE CHEST.

APPLICATKON FILED MAR-29,1916.

Patented; Aug, 8, 1916 mag:-

4 WITNESS IINVENTOR HAL R. STAFFORD, OF PLAINFIELD, NEW JERSEY.

STEAM-ENGINE VALVE-CHEST.

Specification of Letters Patent.

Patented Aug. 3, iilfllh.

Application filed March 29, 1916. Serial No. 87,460.

To all whom it may concern:

Be it known that I, HAL R. STAFFORD, of Plainfield, in the county of Union and State of New'Jersey, have invented a certain new and useful Improvement in Steam-Engine Valve-Chests, of which improvement the following is a specification.

My invention relates to valve chests adapted for the application of steam distribution valves of the piston type in connection with steam engine cylinders having flat valve faces provided for the operation of ordinary slide valves, a valve chest of such character being exemplified in an application for Letters Patent of the United States filed by myself and Henry H. Harrington, under date of March 2, 1916, Ser. No. 81671, uponwhich my present invention is an improvement.

The object of my invention is to provide a-valve chest of the general type of that above referred to, which will afiord' the further advantages of insuring tightness of the joint between the valve chest and cylinder valve face, and enabling a valve stem extension of any desired diameter to be applied, with a reduction of weight as compared with prior constructions.

The improvement claimed is hereinafter fully set forth. I

In the accompanying drawings: Figure 1 is a vertical longitudinal central section through a valve chest and the adjoining portion of the steam cylinder to which it is applied, illustrating an application of my invention; Fig. 2, a bottom plan view of the valve chest; Fig. 3, a vertical transverse section, on the line a: m of Fig. 1; and, Fig. 4, a view, the left hand half of which is a vertical transverse section, on the line a; y of Fig. l, and the right hand half, an end view, in elevation, as seen from the right.

My invention is herein exemplified as applied in connection with a steam engine cylinder, 1, having a flat valve face, 1*, in which are formed transverse rectangular induction and eduction port openings, 2, 2, and an intermediate exhaust port opening, 3, the port openings, 2, 2, being the valve face terminals of induction and eduction ports, 2, 2, leading to opposite ends of the cylinder, 1, and the port opening, 3, being the valve face terminal of an exhaust port, 3, leading to an exhaust pipe. The cylinder which is shown being one which was designed and originally adapted for use with an ordinary valve chest and an inside-= steam pipe, steam admission passages, 2, 2

are formed therein, at opposite ends of the valve face, 1

The construction thusfar described will be seento be that usually adopted in cases wherein a flat slide distribution valve is used to elfect the distribution functions of a cylinder to which steam is supplied through an inside steam pipe.

In the practice of my invention, referring to the specific embodiment thereof which is herein exemplified, I provide an integral valve chest, 10, the middle portion of which is of substantially D or segmental cross sec-- tion and is provided, at bottom, with a fiat face, adapted to abut against the valve face, 1,--0f the cylinder to which the valve chest is applied, and having transverse ports hereinafter described. The valve chest is entirely closed at bottom throughout the end portions of its length, a". 6., those which extend from its middle or valve face portion to its ends, and the bottom walls of said endportions, which are entirely clear of the cylinder, are downwardly the vertical portions of the side walls, as clearly shown in Fig. 3. secured to the cylinder by a plurality of studs, 11, disposed along its outer sides and ends, and fitted with'nuts, ll, flat surfaces located below its top level. The downwardly curved bottom wall of the valve chest acts as the compression member of a truss, and the top wall as the tension member, with the result that the pressure exerted on the'chest by the studs on its sides is extended to its longitudinal central plane, where, with the ordinary construction, it is diflicult to obtain suilicient pressure to insure tightness of the j oint. Some flexibility is also allowed in the wall of the chest, to

compensate the distortion of the valve seat due to the high heat of superheated steam, without loss of pressure on the joint.

Rectangular ports, 2, 2*, and 2, registering, respectively, with the cylinder ports, 2, 2, and}, said latter ports extending from side to side of the port casing hereinafter described, are formed in the valve face portion of the bottom of the valve chest, which is otherwise entirely closed.- An opening, which is'closed by a removable head, 10, is formed in one end of the valve chest, and an opening, closed by a removable head, 10, is formed in its opp site end,

curved between I The valve chest is said head hav bearing on ing a stufling box, 10, for the passage of a valve stem. The valve chest and the nuts of the studs by which it is connected to the cylinder, are inclosed in a light sheet metal casing,.16 A steam supply passage, 10, having a circumferential flange, 10", is formed centrally in the top of the valve chest, .and the lower section, or lower end,

as the case may be, of an outside steam pipe,

15 is secured to the flange, 10", by bolts, 18.

iln order to insure a steam'tight joint between the valve chest and the cylinder, gaskets, which are in the form of joint wires, 6, 6 are interposed between the valve face, 1, of the latter, and the valve face portion of the bottom of the valve chest. As shown in Fig. 1, each of the ports, 2, 2 of the valvevchest, is completely surrounded by a joint wire, 6, and an outer joint wire, 6*, is extended around the ends, and outer sides of said ports, said wire, 6, being interposed between the ports and the atmosphere at the ends of the valve face, and not being exposed to live steam pressure from the interior of the valve chest, and consequently preventing live steam leakage to the atmosphere. Leakage, if any, canoccur only from the steam ports to the exhaust cavity.

As shown in Figs. 3 and 4, the wall of the valve chest is outwardly extended, on both sides, at a level about midway between its bottom and its top, and, below its extended portion, it is continued transversely to form Fig. 1, the top of the port the top of an open ended port casing, 10, which is bored out cylindrically to receive an open ended valve bushing, 7, which is fitted within it. Bridged ports, 7", 7", 7, are formed in the valve bushing the ports 7 7 registering with the ports, 2, 2, of the valve chest, and the port, 7, registering with the valve chest port, 2 As. shown in casing is located sufliciently below the steam supply passage, 10, to provide proper space for the passage of steam therefrom into the open ends of the port casing.

The ports of the valve bushing, 7, and

, those of the valve chest and'cylinder communicating therewith, are controlled by a distribution valve of the piston type, which, in the instance exemplified, comprises two cylindrical heads, 8, 8, each fitted with a suitable packing ring or rings, and an intermedlate spool, 8, which is of substantially elliptical section, the heads and spool being rigidly connected by a bolt, 8 passing through the upper portions of the con- 'nected members and provided with a nut,

8, and by an operating valve' stem, 9, having a collar, 9 and a nut, 9 engaging a thread on one of its ends, the abutting valve members being clamped between said collar and nut. The specific construction of piston distribution valve which is applicable 1s not, however, limited to that seleeted for il1ustration, and any other'suitable known form may be substituted in the discretion of the constructor.

In ordinary practice, the valve stem is continued through and beyond the front of the valve, in order'to form a guiding extension, and, in such case, it is necessary to make the stem of comparatively large di ameter, in order to allow for cutting a thread thereon for the reception of the nut. To obviate this objection, I form the extension, 9, of the valve stem, integral with the nut, 9 which is screwed and pinned on to the valve stem, 9, the extension, 9, working in a casing, 10 cast on the head, 10. The extension may, by this construction, be made of any desired diameter, regardless of that of the stem where it passes through the valve, and considerable weight is saved, not only in the stem, but also in the bosses of the valve follower.

The application of a valve chest embodying my invention enables an existing slide distribution valve to'be replaced by a more effective piston valve, and an outsidesteam pipe to be substituted for an inside steam pipe, without involving disuse or alteratlon of the cylinder, and at comparatively inconsiderable expense. The advantages which it attains in maintaining a steam weight of the valve stem when an extension thereof is desired, will be apparent to those familiar with locomotive engine construction.

I claim as my invention and desire to secure by Letters Patent:

The combination, with an engine cylinder having a transversely ported valve face, of a valve chest fitted at its middle portion on said valve face and having the bottom and end walls of its end portions forming a closure exterior thereto, the bottom walls being downwardly curved between vertically extending side walls, and having also an upper steam supply passage; an integral cylindrically bored open ended port casing having three internal bridged ports, each communicating with one of the valve face ports of the cylinder; and'bolts, disposed laterally on the valve chest and se-' curing said chest to the cylinder. I

HELEN F.. MoDnvrr'r, Jns. MCLAUGHLIN. 

